Aggressive Cancer Research Articles

SQUAMOUS CELL CARCINOMA OF THE SKIN

Introduction: squamous cell carcinoma is steadily increasing year after year, representing a major public health challenge. The mortality rates of dermal squamous cell carcinoma are comparable to those of melanoma, renal carcinoma and oropharyngeal carcinoma. Adequate surveillance, early diagnosis and prompt treatment are essential to reduce the risks of morbidity and mortality. Objective: to detail current information related to cutaneous squamous cell carcinoma, etiology, epidemiology, pathophysiology, histopathology, examination, evaluation, treatment, differential diagnosis, prognosis and complications. Methodology: a total of 37 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 25 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: skin cancer, epidermoid carcinoma, squamous cell, clear cell, Mohs surgery, cutaneous carcinoma. Results: cutaneous squamous cell carcinoma has a multifactorial etiology, with UV radiation being the main risk factor. It is the second most common form of skin cancer in the USA, with a higher incidence in men and fair-skinned, older people. The mortality rate is between 1% and 2%, although in some regions it may be comparable to other more aggressive cancers. It originates from keratinocytes and often has mutations in the tp53 gene. There are several histological subtypes with different characteristics and prognoses. Diagnosis is confirmed by biopsy, and staging is performed with systems such as BWH and AJCC-8, with surgical excision being the preferred intervention. Conclusions: cutaneous squamous cell carcinoma represents an important public health problem, emphasizing the need for prevention and sun protection education programs. Early identification and appropriate treatment are crucial to improve prognosis. The diversity of risk factors, together with the variability in histologic subtypes and their clinical behavior, underscores the importance of a personalized approach to care. In addition, rigorous surveillance is essential in immunocompromised patients, who are at significantly increased risk of developing this neoplasm. Finally, continued research and development of new therapies, such as immunotherapeutic agents, promise to improve clinical outcomes and quality of life for affected patients. KEY WORDS: cancer, carcinoma, skin, squamous, Mohs.

Glioblastoma and Immune Checkpoint Inhibitors: A Glance at Available Treatment Options and Future Directions

Glioblastoma is known to be one of the most aggressive and fatal human cancers, with a poor prognosis and resistance to standard treatments. In the last few years, many solid tumor treatments have been revolutionized with the help of immunotherapy. However, this type of treatment has failed to improve the results in glioblastoma patients. Effective immunotherapeutic strategies may be developed after understanding how glioblastoma achieves tumor-mediated immune suppression in both local and systemic landscapes. Biomarkers may help identify patients most likely to benefit from this type of treatment. In this review, we discuss the use of immunotherapy in glioblastoma, with an emphasis on immune checkpoint inhibitors and the factors that influence clinical response. A Pubmed data search was performed for all existing information regarding immune checkpoint inhibitors used for the treatment of glioblastoma. All data evaluating the ongoing clinical trials involving the use of ICIs either as monotherapy or in combination with other drugs was compiled and analyzed.

Functional interaction between receptor tyrosine kinase MET and ETS transcription factors promotes prostate cancer progression.

Prostate cancer, the most common malignancy in men, has a relatively favourable prognosis. However, when it spreads to the bone, the survival rate drops dramatically. The development of bone metastases leaves patients with aggressive prostate cancer, the leading cause of death in men. Moreover, bone metastases are incurable and very painful. Hepatocyte growth factor receptor (MET) and fusion of genes encoding E26 transformation-specific (ETS) transcription factors are both involved in the progression of the disease. ETS gene fusions, in particular, have the ability to induce the migratory and invasive properties of prostate cancer cells, whereas MET receptor, through its signalling cascades, is able to activate transcription factor expression. MET signalling and ETS gene fusions are intimately linked to high-grade prostate cancer. However, the collaboration of these factors in prostate cancer progression has not yet been investigated. Here, we show, using cell models of advanced prostate cancer, that ETS translocation variant 1 (ETV1) and transcriptional regulator ERG (ERG) transcription factors (members of the ETS family) promote tumour properties, and that activation of MET signalling enhances these effects. By using a specific MET tyrosine kinase inhibitor in a humanised hepatocyte growth factor (HGF) mouse model, we also establish that MET activity is required for ETV1/ERG-mediated tumour growth. Finally, by performing a comparative transcriptomic analysis, we identify target genes that could play a relevant role in these cellular processes. Thus, our results demonstrate for the first time in prostate cancer models a functional interaction between ETS transcription factors (ETV1 and ERG) and MET signalling that confers more aggressive properties and highlight a molecular signature characteristic of this combined action.

Plant-based diets and urological health.

Plant-based diets have grown in popularity owing to multiple health and environmental benefits. Some evidence suggests that plant-based diets are associated with benefits for urological health. In genitourinary oncology, most research has focused on prostate cancer. Clinical trial results suggest a favourable influence of healthy lifestyle modifications including plant-based diets before and after prostate cancer treatment. Epidemiological evidence shows that a diet higher in plant-based and lower in animal-based food is associated with a lower risk of aggressive prostate cancer and better quality-of-life scores than a diet with less plant-based and more animal-based food. Studies on bladder and kidney cancer are scarce, but limited data suggest that vegetarian or plant-forward dietary patterns (increased consumption of fruits and vegetables and minimizing meat) are associated with a lower risk of development of these cancers than dietary patterns with fewer fruits and vegetables and more meat. With respect to benign urological conditions, epidemiological studies suggest that plant-based dietary patterns are associated with a lower risk of benign prostatic hyperplasia and urinary tract infections than non-plant-based dietary patterns. Compared with diets high in animal-based foods and low in plant-based foods, a substantial body of epidemiological evidence also suggests that increased consumption of healthy plant-based food is associated with a lower risk of erectile dysfunction. Plant-based dietary patterns that are high in fruits and vegetables with normal calcium intake, while limiting animal protein and salt, are associated with a lower risk of kidney stone development than dietary patterns that do not follow these parameters. Overall, increasing consumption of plant-based foods and reducing intake of animal-based foods has favourable associations with multiple urological conditions.

Establishment and Validation of Prognostic Nomograms for Nonmetastatic Melanoma of the Limbs—A SEER-Based Study

Background Malignant melanoma, a highly aggressive skin cancer, has remarkable incidence and mortality nowadays. This study aims to explore prognostic factors associated with nonmetastatic cutaneous melanoma of the limbs and to develop nomograms for predicting overall survival (OS) and cancer-specific survival (CSS). Methods The study cohort was derived from the Surveillance, Epidemiology, and End Results database. Univariate Cox regression, Lasso regression, and multivariate Cox regression analyses were conducted to identify prognostic factors and construct nomograms. The receiver operating characteristic (ROC) curve, time-dependent C-index, calibration curve, decision curve analysis (DCA) and Kaplan-Meier method were used to evaluate the accuracy and clinical applicability of the nomograms. Results A total of 15,606 patients were enrolled. Multivariate analysis identified several prognostic factors for OS and CSS including age, sex, histologic type, N stage, tumor thickness, depth of invasion, mitotic rate, ulceration, surgery of primary site, systemic therapy, race, and number of lymph nodes examined. A nomogram incorporating 12 independent predictors for OS was developed, with a C-index of 0.866 (95% confidence interval [CI]: 0.858–0.874) in the training cohort and 0.853 (95% CI: 0.839–0.867) in validation. For CSS, 10 independent predictors and one related factor were included, yielding a C-index of 0.913 (95% CI: 0.903–0.923) in the training cohort and 0.922 (95% CI: 0.908–0.936) in validation. The ROC curve, time-dependent C-index, calibration curve, DCA, and K-M plot demonstrated favorable discrimination, calibration, and clinical utility. Conclusion The developed nomograms provide a precise and personalized predictive tool for risk management of patients with nonmetastatic limb melanoma.

7340 Elucidating the Role of Steroid Hormone Receptors in Anaplastic Thyroid Carcinoma and Pancreatic Ductal Carcinoma Models

Abstract Disclosure: O.M. Stockert: None. C.A. Lange: None. Steroid hormones play important roles in modulating transcription mechanisms in a variety of cancers, including breast cancer, prostate cancer, and ovarian cancer. These interactions are highly context-dependent and regulated by diverse ligands, cofactors, and dynamic post-translational modifications that occur in response to the activation of stress-sensing and oncogenic signaling pathways. Numerous other cancers are associated with elevated steroid hormones, steroid hormone receptors, or both, but have not been studied to explore the possibility of leveraging steroid or steroid receptor (SR)-modulated transcriptional regulation to combat cancerous growth. Two of these cancers are pancreatic ductal adenocarcinoma (PDAC) and anaplastic thyroid carcinoma (ATC). PDAC is an aggressive cancer with a very poor 5-year survival of 8-11%. It is also rapidly growing in incidence and has been shown to be associated with other increasing health conditions, including diabetes and obesity. PDAC is associated with metabolic reprogramming and elevated Progesterone Receptor (PR), Glucocorticoid Receptor (GR), and Mineralocorticoid Receptor (MR) expression. ATC is another aggressive cancer with less than 10% 6-month survival from diagnosis. Like PDAC, ATC has a rapidly increasing incidence and is associated with obesity and high-fat diets. ATC is also associated with elevated cholesterol biosynthesis and elevated GR expression. Herein, we probed public data sets and screened a panel of PDAC and ATC models to demonstrate the expression of mixed SRs. In this study, we take an initial exploration of the hypothesis that related SRs (such as PR, GR, and/or MR) contribute to PDAC and ATC progression and that post-translational modifications, ligand binding, and/or selected cofactors modulate SR actions in the context of activated signaling pathways associated with these aggressive cancers. This study gives us a preliminary understanding of the potential role of steroid hormones and their receptors in the aggressive biology of two deadly and increasingly prevalent endocrine cancers in aging and obese populations. Presentation: 6/3/2024

8109 Cancer-Associated Fibroblasts Correlate with Aggressive Thyroid Cancer Behavior: Insights from Four Large Patient Cohorts

Abstract Disclosure: M.A. Loberg: None. X. George: None. P.J. Courtney: None. H.C. Eric: None. A. Golding: None. B. David: None. M. Alshalalfa: Employee; Self; Veracyte, Inc.. Stock Owner; Self; Veracyte, Inc. Y. Hao: Employee; Self; Veracyte, Inc.. Stock Owner; Self; Veracyte, Inc. J.P. Klopper: Employee; Self; Veracyte, Inc.. Stock Owner; Self; Veracyte, Inc. R.T. Kloos: Employee; Self; Veracyte, Inc.. Stock Owner; Self; Veracyte, Inc.. V. Weiss: None. Thyroid tumor molecular analysis often utilizes fine-needle aspirate (FNA) samples to predict malignancy with high sensitivity. An outstanding question is if molecular sequencing can provide prognostic information to predict disease aggression, potentially informing management. Recently, the composition of the tumor microenvironment, in particular the presence of tumor-promoting fibroblasts, has been associated with aggressive thyroid cancer. However, fibroblast gene expression has not previously been analyzed in thyroid tumor FNA samples. In this work, we detect cancer-associated fibroblast (CAF) gene signatures across 4 distinct bulk RNA sequencing cohorts and confirm detection in FNA samples. Associations between CAF gene signatures and tumor characteristics were explored in: Afirma Genomic Sequencing Classifier (GSC) cohort from FNA (n=47,695), a Memorial Healthcare System (MHS) retrospective FNA cohort with pathology outcome data (n=318), TCGA papillary thyroid cancers (n=496), and a Vanderbilt University Medical Center-University of Washington (VUMC-UW) resection cohort (n=312). Published breast CAF gene sets were used to generate normal fibroblast and CAF subtype scores. Novel thyroid cancer specific CAF gene sets were generated from thyroid cancer single-cell RNA sequencing data. Scores for each gene set were calculated as the average Z-score. Across all cohorts, multiple CAF subsets were enriched in samples with BRAFV600E and papillary histology. The strongest enrichment was in an SFRP2+ CAF subset identified in thyroid cancer single-cell sequencing data. In Afirma GSC FNA samples, SFRP2+ CAFs were enriched in GSC-suspicious and Bethesda V/VI relative to GSC-benign nodules (Wilcoxon p value < 2e-[1]6 for all). In TCGA, SFRP2+ CAFs were associated with extrathyroidal extension, advanced disease stage, and aggressive histology. In the MHS cohort of 318 malignant FNA samples, SFRP2+ CAFs were significantly higher in patients with vascular invasion or lymph node metastasis (LNM) (OR:2.75 [95% CI 1.63-4.75], p=4e-5). In the VUMC-UW cohort, SFRP2+ CAFs were associated with shorter progression-free survival (PFS) (p=0.0033). In summary we created a novel thyroid cancer-specific CAF gene signature that is elevated in BRAFV600E+ and aggressive thyroid cancers across multiple large patient cohorts. We also demonstrated the ability to detect these CAF signatures in thyroid FNAs using the Afirma GSC molecular testing platform, with enrichment in suspicious and malignant samples. Amongst the CAF scores tested, thyroid-specific CAF subsets had the highest prognostic potential, and SFRP2+ CAFs, specifically, were associated with shorter PFS, tumor invasion and LNM. Together, these results highlight the potential of interrogating the thyroid tumor stroma in FNA using RNA-based assays to inform prognosis and possibly management. Presentation: 6/3/2024

Crispr-mediated genome editing reveals a preponderance of non-oncogene addictions as targetable vulnerabilities in pleural mesothelioma

Pleural mesothelioma (PM) is an aggressive cancer with limited treatment options. In particular, the frequent loss of tumor suppressors, a key oncogenic driver of the disease that is therapeutically intractable, has hampered the development of targeted cancer therapies. Here, we interrogate the PM genome using CRISPR-mediated gene editing to systematically uncover PM cell susceptibilities and provide an evidence-based rationale for targeted cancer drug discovery. This analysis has allowed us to identify with high confidence numerous known and novel gene dependencies that are surprisingly highly enriched for non-oncogenic pathways involved in response to various stress stimuli, in particular DNA damage and transcriptional dysregulation. By integrating genomic analysis with a series of in vitro and in vivo functional studies, we validate and prioritize several non-oncogene addictions conferred by CDK7, CHK1, HDAC3, RAD51, TPX2, and UBA1 as targetable vulnerabilities, revealing previously unappreciated aspects of PM biology. Our findings support the growing consensus that stress-responsive non-oncogenic signaling plays a key role in the initiation and progression of PM and provide a functional blueprint for the development of unprecedented targeted therapies to combat this formidable disease.

7466 The Effects Of Various Forms Of Diabetes On Features Of Tumor Aggressiveness In Thyroid Cancer

Abstract Disclosure: R.D. Paparodis: None. E. Karvounis: None. A. Kapezanou: None. S. Livadas: None. G. Simeakis: None. D.P. Askitis: None. I. Androulakis: None. N.G. Angelopoulos: None. D. Zianni: None. A. Rizoulis: None. A. Boniakos: None. I. Perogamvros: None. D. Bantouna: None. J.C. Jaume: None. Introduction: Diabetes has been linked to increased risk for several cancers and aggressiveness of tumor behavior. A link between thyroid cancer and diabetes appears controversial in the literature as of yet. We designed the present study to assess whether autoimmune (type 1 + LADA = DM1) or type 2 diabetes (DM2) are associated with more aggressive thyroid cancers compared to those found in non-diabetic (non-DM) individuals. Methods: We retrospectively reviewed data from patients undergoing thyroid surgery in 10 Endocrinology and Endocrine Surgery Clinics throughout Greece over 2 years. We collected data on history and type of diabetes, pre-existing to the thyroid surgery, its treatments and duration, the preoperative thyroid function tests and the surgical pathology findings. We compared the incidence of various histological types of thyroid cancer and the features of tumor aggressiveness between patients with diabetes and those with normal glucose homeostasis (non-DM) (DM1 vs. DM2 vs. non-DM). Results: Overall, n=808 subjects with thyroid cancer were included: n=571 were females (70.7%), age 47.3 ± 14.3 years, BMI 27.0 ± 5.0 Kg/m2, mean TSH 1.99 ± 2.21 mIU/L; n= 692 were non-DM, n=10 had DM1 and n=107 had DM2. Histology revealed n=5 poorly differentiated / anaplastic, n=13 medullary, n=12 Hürthle cell, n=17 follicular and n=773 papillary thyroid cancers (PTC); n=20 (2.5%) with aggressive histological subtypes of PTC, n=5 (0.6%) with distant metastases (MET), n=199 (24.6%) with extrathyroidal extension (ETE), n=419 (51.9%) with capsular invasion (CI), n=225 (27.8%) with lymph nodes involvement (LNi) and n=23 with cancer recurrence (CR) (2.8%). The incidence of aggressive histological types, CR, MET or number of I-131 treatments were not different between groups (p>0.05). ETE, CI and LNi were significantly more common in non-DM compared to both diabetes groups, while gross ETE was more common in DM2 over DM1 and non-DM (p<0.001). Conclusions: More DM1 than DM2 seem to confer a protective effect on several features of cancer aggressiveness in affected individuals. On the other hand, more DM2 than DM1 seems to significantly promote gross ETE. No effect was observed pertaining to the risk for more aggressive tumors or histological subtypes of PTC. Although aggressiveness of thyroid cancer seems controlled in DM1 and to a lesser degree in DM2 the complex interplay between autoimmunity, hyperglycemia and thyroid cancer biology requires larger sample size to better determine causative effects. Presentation: 6/2/2024

7466 The Effects of Various Forms of Diabetes on Features of Tumor Aggressiveness in Thyroid Cancer

Abstract Disclosure: R.D. Paparodis: None. E. Karvounis: None. A. Kapezanou: None. S. Livadas: None. G. Simeakis: None. D.P. Askitis: None. I. Androulakis: None. N.G. Angelopoulos: None. D. Zianni: None. A. Rizoulis: None. A. Boniakos: None. I. Perogamvros: None. D. Bantouna: None. J.C. Jaume: None. Introduction: Diabetes has been linked to increased risk for several cancers and aggressiveness of tumor behavior. A link between thyroid cancer and diabetes appears controversial in the literature as of yet. We designed the present study to assess whether autoimmune (type 1 + LADA = DM1) or type 2 diabetes (DM2) are associated with more aggressive thyroid cancers compared to those found in non-diabetic (non-DM) individuals. Methods: We retrospectively reviewed data from patients undergoing thyroid surgery in 10 Endocrinology and Endocrine Surgery Clinics throughout Greece over 2 years. We collected data on history and type of diabetes, pre-existing to the thyroid surgery, its treatments and duration, the preoperative thyroid function tests and the surgical pathology findings. We compared the incidence of various histological types of thyroid cancer and the features of tumor aggressiveness between patients with diabetes and those with normal glucose homeostasis (non-DM) (DM1 vs. DM2 vs. non-DM). Results: Overall, n=808 subjects with thyroid cancer were included: n=571 were females (70.7%), age 47.3 ± 14.3 years, BMI 27.0 ± 5.0 Kg/m[2], mean TSH 1.99 ± 2.21 mIU/L; n= 692 were non-DM, n=10 had DM1 and n=107 had DM2. Histology revealed n=5 poorly differentiated / anaplastic, n=13 medullary, n=12 Hürthle cell, n=17 follicular and n=773 papillary thyroid cancers (PTC); n=20 (2.5%) with aggressive histological subtypes of PTC, n=5 (0.6%) with distant metastases (MET), n=199 (24.6%) with extrathyroidal extension (ETE), n=419 (51.9%) with capsular invasion (CI), n=225 (27.8%) with lymph nodes involvement (LNi) and n=23 with cancer recurrence (CR) (2.8%). The incidence of aggressive histological types, CR, MET or number of I-131 treatments were not different between groups (p>0.05). ETE, CI and LNi were significantly more common in non-DM compared to both diabetes groups, while gross ETE was more common in DM2 over DM1 and non-DM (p<0.001). Conclusions: More DM1 than DM2 seem to confer a protective effect on several features of cancer aggressiveness in affected individuals. On the other hand, more DM2 than DM1 seems to significantly promote gross ETE. No effect was observed pertaining to the risk for more aggressive tumors or histological subtypes of PTC. Although aggressiveness of thyroid cancer seems controlled in DM1 and to a lesser degree in DM2 the complex interplay between autoimmunity, hyperglycemia and thyroid cancer biology requires larger sample size to better determine causative effects. Presentation: 6/2/2024

7324 Regulation of Super Enhancers by Phosphorylated Progesterone Receptors Drives Breast Cancer Stem Cell Expansion

Abstract Disclosure: N. Gillis: None. C.A. Lange: None. Current treatments for estrogen receptor (ER) positive breast cancer largely target rapidly dividing tumor cells. However, aggressive breast cancers often contain long-lived and weakly proliferative cancer stem cells (CSCs) that readily escape treatments aimed at cycling cells. We previously reported that progesterone receptors (PR) and their target genes aid the growth of these CSCs and help them evade anti-estrogen therapy. As proliferation and stemness are directed by separate signaling pathways that lead to the expression of distinct gene programs, it's crucial to understand how PR facilitates this cellular transformation at the genomic level. Establishing a gene expression program that may limit proliferation but encourages stemness requires coordination between transcription factors and their coregulators to alter the nuclear microenvironment and chromatin landscape.To reveal these mechanisms, we profiled PR and ER genomic binding using CUT&RUN in the T47D luminal breast cancer cell line grown in ultra-low attachment (3D) mammosphere conditions. Our analysis of genomic binding profiles displayed a pattern of PR/ER co-occupancy at distant sites more than 10 kilobases away from the nearest transcriptional start site. We used Rank Ordering of Super Enhancer (ROSE) analysis on these PR/ER binding sites to predict which are likely super enhancer elements capable of coordinating the regulation of multi-gene subsets. We employed a genetic approach to directly test the function of novel enhancer sites linked to PR-target genes by disrupting the PR/ER binding with a dCas9-KRAB construct directed to the predicted enhancer elements. We propose that abnormal growth factor signaling in breast cancer cells permits PR/ER complex formation which promotes expression of genes that induce endocrine resistance and CSC expansion through regulation of super enhancer elements. Further studies to elucidate these mechanisms are ongoing. Understanding the intricacies of PR/ER crosstalk is the crucial next step in developing new therapies that target PR-driven processes in ER+ breast cancers. Presentation: 6/3/2024

12205 Challenging Case Of Anaplastic Thyroid Cancer With Unusual Histological Features: A Diagnostic Dilemma With High Grade Sarcoma

Abstract Disclosure: B. Gautam: None. B. Tiwari: None. M.S. Hossain: None. S. Hossain: None. S.C. Kumar: None. H. liao: None. Introduction: Anaplastic thyroid carcinoma (ATC) is a rare but highly aggressive thyroid cancer accounting for < 2% of cases, characterized by its rapid growth, extensive local invasion, and poor prognosis. Distinguishing ATC from other high-grade sarcomas, such as leiomyosarcoma, is challenging due to shared morphological features and overlapping immunoprofiles. We present a case involving a 73-year-old male presenting with rapidly growing neck mass, leading to diagnostic challenges differentiating between ATC and high-grade sarcomas. Case presentation: A 73-year-old male presented to ED with a rapidly growing painful neck mass for last 3 months, associated with dysphagia, dyspnea & dysphonia. He denied any fever, chills, weight loss and symptoms of hyperthyroidism or hypothyroidism. No personal or family history of thyroid cancer. On physical exam: vitals were normal, Neck exam revealed a left sided neck mass, mobile with deglutition, hard in consistency associated with hoarseness of voice. No stridor or wheeze noted on auscultation. Physical exam was otherwise normal. Laboratory tests showed normal CBC, CMP and TSH 1.45 mIU/L, T4 9.7 ug/dl. CT neck with contrast showed 5.4 x 5.6 x 8.2 cm large lobulated left thyroid mass with rightward airway deviation & substernal extension. Ultrasonogram of thyroid showed 9.6 x 5.3 x 3.3 cm left thyroid lobe with internal calcifications & extrathyroidal extension with several abnormal appearing cervical lymph node, largest measuring 4.9 x 2.4 x 3.3 cm. CT chest/abdomen/pelvis with contrast showed multiple bilateral lung nodules measuring up to 1.5 cm and 1.4 x 1.3 cm left gluteal soft tissue mass. IR-guided left neck mass biopsy was suggestive of primary spindle cell neoplasm with initial immunoprofiles consistent with a high-grade sarcoma, favoring leiomyosarcoma. Given the rapid growth of the neck mass with associated dyspnea, left thyroidectomy was performed and surgical pathology was suggestive of a high-grade sarcoma. However, subsequent pathology review made a final diagnosis of ATC, based on morphologic & immunohistochemical profile showing tumor cells strongly positive for p53 and Desmin with few cells positive for PAX-8, Cam 5.2 and CD68, and negative thyroglobulin, TTF-1, CK7, CK20, CK MNF116, pancytokeratin AE1/AE3 and CK5/6. Thyroseq revealed a distinctive molecular profile specifically positive for TERT and TP53 supporting diagnosis of ATC. Discussion: This case highlights the diagnostic dilemma posed by the resemblance between ATC and high-grade sarcomas due to overlapping clinical, morphological and immunohistology features. While both malignancies may exhibit similar morphological features, specific immunohistochemistry profiles along with molecular testing aid in distinguishing between them and guiding appropriate treatment strategies. Presentation: 6/1/2024

Kinase library screening identifies IGF-1R as an oncogenic vulnerability in intrahepatic cholangiocarcinoma stem-like cells

BackgroundIntrahepatic cholangiocarcinoma (iCCA) is a highly aggressive cancer of the peripheral bile ducts and is recognized by the abundance of cancer stem-like cells (CSCs) within the tumor mass. While CSC markers in iCCA are well-defined, the molecular vulnerabilities of this subpopulation remain elusive. MethodsThe 96-well, three dimensional (3D) tumorsphere culture was adapted from a well-established CSC model, validated for CSC markers through gene expression analysis. Kinase library screening was then conducted to reveal potential oncogenic vulnerable pathways. RNA interference was utilized to stably silence the candidate gene in three iCCA cell lines and its impact on iCCA cell proliferation and tumorsphere formation efficiency (TFE) was evaluated. ResultsKinase inhibitor library screening identified the top 50 kinase inhibitors crucial for tumorsphere viability, with 11 inhibitors targeting the IGF-1R/PI3K/AKT axis. Further dose-dependent analysis of the top ‘hit’ inhibitors confirmed IGF-1R as the candidate molecule. Upon stably silencing of IGF-1R, all three iCCA cell lines exhibited decreased AKT activation, impeded proliferation and reduced TFE, indicating a decline in CSC subpopulations. ConclusionsIGF-1R plays a critical role in maintaining iCCA-stem like cell populations. General significanceOur data highlight the potential utility of IGF-1R as a prognostic marker of iCCA and a therapeutic target for eliminating its CSC subpopulation.

7888 Mitotane Induces Different Modes Of Cell Death In Treatment Resistant And Sensitive Models Of Adrenocortical Carcinoma

Abstract Disclosure: S. Feely: None. N. Mullen: None. C. Hong: None. C. Hantel: None. W.E. Rainey: None. M.C. Dennedy: None. Adrenocortical carcinoma (ACC) is a rare aggressive cancer with poor survival. Adjuvant mitotane is the only approved drug for treatment of ACC. It improves survival but its use is limited by poor tolerability and drug resistance. For metastatic ACC, combination chemotherapy, using mitotane and etoposide, doxorubicin, and cisplatin improves survival, but efficacy is limited. Better understating the cytotoxic mechanisms of mitotane offers potential to develop improved therapeutic options for ACC. To investigate the underlying mechanisms in vitro, human ACC cells (HAC15 and H295R), in monolayer cell culture were treated with increasing concentrations of mitotane. Cell death was evaluated at 6 and 24 hours using flow cytometry analysis of Annexin V and Sytox Blue. This was complemented by Incucyte ® Live-Cell Analysis System imaging of annexin V and Sytox Blue staining. Expression of the markers of apoptosis, cleaved caspase 3, and necroptosis, phosphorylated MLKL and RIPK1 was measured at 6 and 24 hours. Mitotane significantly reduced the viability of H295R cells at 6 and 24 hours at the therapeutic concentration of 50uM (p>0.0001), thereby demonstrating treatment-sensitivity. In HAC15 cells, a supratherapeutic dose of 200uM was needed to significantly reduce viability (p>0.05) at 24 hours, indicating resistance to mitotane treatment at therapeutic concentrations. There was increasing Annexin V fluorescence with increasing mitotane concentration in H295R and HAC15 cells ar 6 and 24 hours without higher coinciding staining with Sytox Blue. Video analysis demonstrated these findings. Cleaved caspase 3 expression was associated with mitotane-induced cell death in H295R cells at 6 and 24 hours, indicating apoptosis. HAC15 cells demonstrated cleaved caspase 3 expression only at the highest concentration of mitotane exposure (600uM) at 6 hours, without appreciable expression at 24 hours. Phosphorylated-MLKL and RIPK1 expression was seen in controls and all mitotane doses in both cell lines at both timepoints, indicating necroptosis. In this study, H295R cells, representing a treatment-sensitive model of Mitotane undergo both apoptotic and necroptotic cell death at 6 and 24 hours of mitotane exposure. In contrast, HAC15 cells, demonstrated relative treatment resistance to mitotane, and undergo necroptotic cell death only. These results highlight the importance of understanding and targeting non-apoptotic and necroptotic cell death pathways, particularly when evaluating mechanisms of treatment resistance in ACC. Given the difference in the mechanism of cell death in treatment-sensitive and treatment-resistant cells, further exploration of necroptosis is necessary to better understand how ACC cells may manifest treatment resistance. Presentation: 6/1/2024

7272 Antineoplastic Effect of Cabozantinib in Primary and Continuous Human Anaplastic Thyroid Cancer Cells

Abstract Disclosure: G. Elia: None. S. Ferrari: None. F. Ragusa: None. V. Mazzi: None. A. Patrizio: None. E. Balestri: None. C. Botrini: None. L. Rugani: None. E. Barozzi: None. C. La Motta: None. P. Fallahi: None. A. Antonelli: None. Anaplastic thyroid cancer (ATC) is a highly aggressive cancer with a low median survival of about 6-10 months. The standard treatment include surgery, external hyperfractionated radiation therapy, and chemotherapy. However, these therapies are not effective and new therapeutical approaches are needed. Tyrosine kinase inhibitors (TKI) are a class of drugs able to inhibit different pathways that results inappropriately activated in cancer cells.To date no studies evaluated the effect of cabozantinib in primary human ATC cells, and in ATC continuous cell line in vitro. We aimed to test the efficacy of cabozantinib a multiTKI acting against VEGFR 1,2, c-MET, and RET (recently approved for aggressive differentiated thyroid cancer) in primary human ATC cells, and in ATC continuous cell line (8305C, CAL-62) in vitro. Therefore, for primary ATC cells we collected surgical thyroidal tissues from five patients with ATC, from thyroid biopsy at the moment of first surgical operation, and we tested the effect of cabozantinib. Cabozantinib showed its efficacy in inhibiting cell proliferation, and also in increasing apoptosis (p < 0.05) both in primary and in continuous ATC cells. In conclusion, cabozantinib demonstrated a good antineoplastic activity in human ATC cells in vitro. These results open the way for a possible clinical use of cabozantinib in patients with ATC, and are important for a personalized therapeutic approach to be tailored to each patient avoiding the administration of ineffective drugs. Presentation: 6/1/2024

Widely-targeted in silico and in vitro evaluation of veratrum alkaloid analogs as FAK inhibitors and dual targeting of FAK and Hh/SMO pathways for cancer therapy: A critical analysis

Focal Adhesive Kinase (FAK), a key player in aggressive cancers, mediates signals crucial for progression, invasion, and metastasis. Despite advances in targeted therapies, drug resistance is still a challenge, and survival rates remain low, particularly for late-stage patients, emphasizing the need for innovative cancer therapeutics. Cyclopamine, a veratrum alkaloid, has shown promising anti-tumor properties, but the search for more potent analogs with enhanced affinity for the biological target continues.This study employs a hybrid virtual screening approach combining pharmacophore model-based virtual screening (PB-VS) and docking-based virtual screening (DB-VS) to identify potential inhibitors of the FAK catalytic domain. PB-VS on the PubChem database yielded a set of hits, which were then docked with the FAK catalytic domain in two stages (1st and 2nd DB-VS). Hits were ranked based on docking scores and interactions with the active site. The top three compounds underwent molecular dynamics simulations, alongside two control compounds (SMO inhibitor(s) and FAK inhibitor(s)), to assess stability through RMSD, RMSF, Rg, and SASA analyses. ADMET properties were evaluated, and compounds were filtered based on drug-likeness criteria.Molecular dynamics simulations demonstrated the stability of compounds when complexed with the FAK catalytic domain. Compounds 16 (−25 kcal/mol), 88 (−27.47 kcal/mol), and 87 (−18.94 kcal/mol) exhibited comparable docking scores, interaction profiles, stability, and binding energies, indicating their potential as lead candidates. However, further validation and optimization through quantitative structure-activity relationship (QSAR) studies are essential to refine their efficacy and therapeutic potential. The in vitro cell-based assay demonstrated that compound 101PF, a FAK inhibitor, significantly inhibited the proliferation and migration of A549 cells. However, the results regarding the combined effects of FAK and SMO inhibitors were inconclusive, highlighting the need for further investigation. This study contributes to developing more effective anti-cancer drugs by improving the understanding of potential cyclopamine-based veratrum alkaloid analogs with enhanced interactions with the FAK catalytic domain.

C-Myc inhibition and p21 modulation contribute to unsymmetrical bisacridines-induced apoptosis and senescence in pancreatic cancer cells.

Pancreatic cancer (PC) is one of the most aggressive cancers and is the seventh leading cause of cancer-related death worldwide. PC is characterized by rapid progression and resistance to conventional treatments. Mutations in KRAS, CDKN2A, TP53, SMAD4/DPC4, and MYC are major genetic alterations associated with poor treatment outcomes in patients with PC. Therefore, optimizing PC therapy is a tremendous challenge. Unsymmetrical bisacridines (UAs), synthesized by our group, are new promising compounds that have exhibited high cytotoxicity and antitumor activity against several solid tumors, including pancreatic cancer. The cellular effects induced by UAs in PC cells were evaluated by MTT assay (cell growth inhibition), flow cytometry, and fluorescence and light microscopy (cell cycle distribution, apoptosis, and senescence detection). Analysis of the effects of UAs on the levels of proteins (c-Myc, p53, SMAD4, p21, and p16) was performed by Western blotting. Apoptosis was the main triggered mechanism of death after UAs treatment, and induction of the SMAD4 protein can facilitate this process. c-Myc, which is one of the molecular targets of UAs, can participate in the induction of cell death in a p53-independent manner. Moreover, UAs can also induce accelerated senescence through the upregulation of p21. Notably, senescent cells can die via apoptosis after prolonged exposure to UAs. UAs have emerged as potent anticancer agents that induce apoptosis by inhibiting c-Myc protein and triggering cellular senescence in a dose-dependent manner by increasing p21 levels. Thus, UAs exhibit desirable features as promising candidates for future pancreatic anticancer therapies.

Roles of ZEB1 and ZEB2 in E-cadherin expression and cell aggressiveness in head and neck cancer.

Zinc finger E-box binding homeobox 1 (ZEB1) has been identified as a key factor in cancer cell differentiation and metastasis, and has been well studied in the field of cancer cell biology. ZEB2 has a highly similar conformation to ZEB1, but its role in head and neck squamous cell carcinoma (HNSCC) cells is not fully understood. Here, we separately overexpressed ZEB1 and ZEB2 in C57BL/6 mouse oral cancer (MOC) cells and investigated their cellular characteristics, including E-cadherin levels, motile properties, chemoresistance, and metastatic ability in immunocompetent mice. Both ZEB1 and ZEB2 overexpression reduced epithelial traits and converted cells to an aggressive phenotype. Surprisingly, ZEB1 overexpression increased the endogenous level of ZEB2 in MOC cells, and vice versa. The molecular mechanisms underlying these findings remain unclear. However, the in vitro anchorage-independent growth of MOC cells overexpressing ZEB2 was considerably greater than that of MOC cells overexpressing ZEB1. These findings suggest that ZEB2, like ZEB1, has the ability to induce the differentiation of cancer cells into those with highly aggressive traits.

KRT14 as a potential prognostic marker for metastasis in metaplastic breast carcinoma

Metaplastic breast cancer (MBC) is an aggressive breast cancer subtype with poor prognosis. To elucidate underlying genomic aberrations driving MBC, we conducted integrated transcriptomic analyses of MBC tumors and basal breast cancer cell lines with various transitioning phases (xE = epithelial phase clone, xM = mesenchymal phase clone and xEM = Epithelial-mesenchymal clone). Differential gene expression analysis between MBC vs non-MBC samples as well as between epithelial-mesenchymal (xEM) transitioning cells vs parental cells revealed 12 commonly dysregulated genes intersected from both the datasets meditates pathways governing EMT, migration, proliferation and metastasis. Further investigation onto those genes based on multi-omics approaches that include survival analysis, correlated expression patterns and interactomics indicated KRT14 had a key role in promoting MBC aggression through Epithelial mesenchymal transition leading to metastasis. Moreover, NPR3 was found to be a possible link between KRT14 and EMT in metastasis. To our knowledge, this is the first evident gene expression study to investigate the potential association between the expression of KRT14 and NPR3 and metastasis in MBC, and their potential involvement in the epithelial-mesenchymal transition (EMT) process. These mechanistic and prognostic insights gained can lead to targeted therapeutics against this rare, refractory disease. Overall, this work highlights the effectiveness of integrated multi-omics in revealing gene expression pattern and predictive biomarkers for metaplastic breast cancer subtypes with poor prognosis.

Compromised CDK12 activity causes dependency on the high activity of O-GlcNAc transferase.

O-GlcNAc transferase (OGT) coordinates with regulators of transcription, including cyclin-dependent kinase 12 (CDK12), the major transcription elongation kinase. Here, we use inhibitor- and knockdown-based strategies to show that co-targeting of OGT and CDK12 is toxic to prostate cancer cells. OGT catalyzes all nucleocytoplasmic O-GlcNAcylation and due to its essentiality in higher eukaryotes, it is not an ideal drug target. Our glycoproteomics-data revealed that short-term CDK12 inhibition induces hyper-O-GlcNAcylation of the spliceosome-machinery in different models of prostate cancer. By integrating our glycoproteomics-, gene essentiality- and clinical-data from CDK12 mutant prostate cancer patients, we identify the non-essential serine-arginine protein kinase 1 (SRPK1) as a synthetic lethal partner with CDK12-inactivation. Both normal and cancer cells become highly sensitive against inhibitors of OGT and SRPK1 if they have lowered activity of CDK12. Inactivating mutations in CDK12 are enriched in aggressive prostate cancer, and we propose that these patients would benefit from therapy targeting the spliceosome.